WCP/Fe-C 复合材料的界面反应和基体合金化研究

利用离心铸造成型碳化钨颗粒(WCP ) 增强Fe-C 基体合金的复合结构空心圆柱体, 采用宏观测量、X 射线衍射分析和扫描电镜(SEM ) 与能谱(EDS) 的微观分析, 对WCP/Fe-C 界面反应和基体合金化研究。结果表明, 在转速800～ 1200 r/m in离心铸造机上获得了外径167mm , 内径87mm , 高67mm 的空心圆柱体, 其表面层为16～ 20mm 大断面WCP/Fe-C 复合材料, 芯部为Fe-C 基体合金。铸造碳化钨颗粒(CTCP ) 的表面被高温Fe-C 基体合金熔融体部分溶解, 甚至解体; 原位( in2situ) 自生成细小短棒状WC 和W₂C 先共晶析出相; 远离CTCP , 分布游离的细小颗粒状和网状WC、W ₂C、Fe₃W ₃C₂Fe₄W ₂C、Cr₇C₃ 和Fe₃₂C 碳化物。由于CTC_P 部分溶解和扩散作用, 复合结构空心圆柱体的Fe-C合金基体被不同程度合金化。 

INVESTIGATION ON THE INTERFACE REACTIONS AND MATRIX ALLOYING OF WC_P/Fe-C COMPOSITES

Investigation on the interface reactions and matrix alloying of WCP/Fe-C composites was performed by centrifugal casting a hollow cylinder with composite structure and measuring macrostructures and X ray diffraction analysis and SEM micrography with EDS analysis. In the present work condition, the cylinder, dimensioned by outer diameter 167 mm and inner diameter 87 mm and highness 67 mm, consists of WCP/Fe-C composites surface layer with 16～20 mm heavy cross section and Fe C alloy matrix core. Results show that the surface of CTC particles was partially dissolved by Fe containing melt,even divided.The fine short stick like crystallites, being WC and W 2C primary phase before eutectic, are in situ separated near to the surface of CTC particles. Far from the CTC particles, some separated, fine particle and web WC, W 2C,Fe 3W 3C Fe 4W 2C,Cr 7C 3 and Fe 3C carbide crystallites, are distributed on the matrix of WCP/Fe-C composite. Fe C alloy matrix of the hollow composite cylinder is alloyed in different levels, due to the partial dissolve and diffusion of CTC particles.